Off-grid EV charging

From off-grid electric vehicle (EV) charging to a desire for more sustainable transport, EV owners share the stories behind their choices with Robyn Deed.

Until recently, number one on Ross Ulman’s ‘bucket list’ was owning an EV and charging it from the sun (a ReNew kind of bucket list!). He got to tick off that item late last year after buying a secondhand Nissan Leaf, with 10,000 km on the clock, around the same time as he and his wife Vivienne moved to their new energy-efficient off-grid home near Daylesford.

He bought the Leaf from a friend who was upgrading to a larger EV, a Mitsubishi Outlander, which, with its ‘range extending’ petrol engine meant the friend could do without a second fossil-fuelled car. Pure EVs are probably uncommon in the country, says Ross, because of the longer distances travelled and the resulting ‘range anxiety’. Range doesn’t cause Ross problems, however. He plans ahead for his longest trip, about 90 km return to Ballarat for work, which is well within the 120 km range of his fully charged Leaf (the quoted range is 170 km, but he finds he only gets about 120 km with the hilly driving around Daylesford). His main driving is into and around Daylesford, about 15 km, all easily doable without mid-trip recharging.

He doesn’t drive the Leaf for his occasional trips to Melbourne, though driving there from Daylesford would be no problem, and charging in Melbourne would be no problem also, as there are charging stations in the city. However, the trip back to Daylesford would be problematic as, even if leaving Melbourne with full charge, the Leaf would need a further charge, albeit a short one, on the journey home—the increase in altitude uses more power than the downhill run into Melbourne. Ross is planning to upgrade in a couple of years, when a Leaf with double the range is slated to become available. He hopes that affordable EVs with double or triple the range of the current Leaf will make them more mainstream. And leadership from government is also needed. “EVs are the future of the car industry,” he says, “but we really need strong public policy with incentives and infrastructure investment.”

One interesting aspect of Ross’s EV is that it’s charged off-grid. He only charges the EV during the day when the sun is shining, a bit different from the usual overnight charging regime. The off-grid system, designed by Off-Grid Energy Australia, is AC-coupled, which Ross says has been fantastic, enabling him to charge the EV at the same time as the house batteries are charged: any draw from the house or car comes direct from the solar panels (when they’re producing energy), rather than from the house battery, reducing battery cycling.

The solar PV system is oversized (10.5 kW solar and 40 kWh batteries), which the system designers say should be sufficient to charge both the house batteries and the car even on cloudy days. So far (they’ve had the system since November 2014) there have been a couple of runs of four or five cloudy days and sufficient energy has indeed been generated.

Ross plans to work around his solar system production to avoid over-discharge of the batteries. If there’s a run of rainy days, he won’t charge the Leaf: if it has enough remaining charge he’ll drive it short distances; and, if it hasn’t, then he’ll make alternative transport arrangements, such as using their petrol vehicle or public transport. So what’s next for Ross’s bucket list? Well, there’s that Leaf upgrade in a couple of years. Or perhaps it’s just time to settle back and enjoy demonstrating that off-grid and EV can go together.

Read more stories about EV ownership in Best EVer stories: Electric vehicle owners share the love in ReNew 131.